Folding device for use in connection with box making machines



M. PROPPER 3,377,927

FOLDING DEVICE FOR USE IN CONNECTION WITH BOX MAKING MACHINE3 A ril 16, 1968 Filed April 27, 1965 United States Patent FOLDING DEVICE FOR USE IN CONNECTION WITH BOX MAKING MACHINES Mathias Propper, Dusseldorf-Wersten, Germany, assignor to Boring u.A., Arbeitsgemeinschaft fur Entwicklung von Papierverarbeitungsmaschinen, Dusseldorf-Reisholz, Germany Filed Apr. 27, 1965, Ser. No. 451,130

5 Claims. (Cl. 9349) ABSTRACT OF THE DISCLOSURE Apparatus for folding over the trailing flaps of carton blanks in which a hook shaped folding arm suspended from a chain engages beneath the trailing flaps from the rear and tilts them upwardly while the said arms are then caused to swing forwardly to fold the flaps down against the blanks.

The present invention relates to a folding device for use in connection with box making machines which is intended for folding the rear flaps of flat folded boxes adapted to be unfolded and which can be used as supplementary device in connection with heretofore known box making machines.

In connection with the production of boxes, it is customary to produce the individual boxes in a certain rhythm. In my co-pending application Ser. No. 450,219, filed Apr. 22, 1965, there has been described a continuous method of making flat folded boxes on box making machines provided with belt means for advancing the box blanks and also equipped with an adhesive applying device while the blank passes through the box making machine in one direction and without the necessity of maintaining a certain rhythm. This machine folds the box blanks into the finished flat folded boxes.

The device for carrying out the said method employs folding means for folding the rear flaps of the blank, said folding means being actuated mechanically or optically by the respective blank to be folded.

It is an object of the present invention to improve the above mentioned stepwise operating folding device.

It is another object of this invention to provide a folding device for the above mentioned purpose which will operate in a continuous manner.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing diagrammatically illustrating a side view of a folding device according to the present invention.

The folding device according to the invention for use in connection with box making machines for folding the rear flap of flat folded boxes adapted to be unfolded is characterized primarily in that above the belts which feed the box blanks there is provided a circulating chain moving at a relatively high speed and provided with tiltably arranged folding hooks. The arrangement is such that the lower chain section is slightly ascending in the direction of movement of the lower chain section, and that the folding hooks over the first portion of their movement in the lower chain section are tiltable rearwardly whereas in the last portion of the lower chain section the folding hooks are non-tiltably connected to the chain.

The folding hooks are preferably Z-shaped and are provided with an abutment angle for limiting the tilting movement in the direction of movement of the chain. A control plate cooperating with those legs of the Z-shaped folding hooks which are arranged within the chain is provided'for controlling the tilting movement of the folding hooks. Said control plate is along the major portion of its circumference substantially evenly spaced from the chain 3,377,927 Patented Apr. 16, 1968 and only in the first portion of the lower section of the chain is provided with a cutout or recess and a merging portion from said cutout to the remainder of said plate. This merging portion makes it possible for the folding hooks passing thereover to tilt rearwardly when the'folding hook moves Onto a box blank moving at a lower speed.

Referring now to the drawing in detail, above the feeding belts (not shown) for the box blank 1, there are in conformity with the present invention provided two sprocket wheels 47 and 48 over which passes an endless chain 40. This chain, the lower section of which ascends slightly in the direction of movement thereof, carries a plurality of folding books 41 which are substantially uniformly spaced from each other and are connected to the chain by means of supports 49.

As will be evident from the drawing, these folding hooks 41 are preferably Z-shaped while a leg 44 of each folding hook 41 is located within the path of movement of chain 40. In order to be able to control the movement of the folding hooks 41, there is provided a control plate 63 the major circumferential portion of which is substantially evenly spaced from chain 40. Approximately over the first half (when looking in the direction of movement of the lower chain section) of its lower portion said control plate 43 is provided with a cutout 45 so as to permit a backward tilting of the folding hooks 41. The merging portion 46 adjacent the end of the cutout 45 permits the folding hook 41 to tilt back into its substantially vertical position with regard to chain 40. Abutment angles 42 limit this backward tilting movement. It will be appreciated that outside cutout 45 the legs 44 slide on control plate 43.

The operation of the device according to the present invention will be evident from the drawing. It will be obvious that in view of the fact that the folding hooks 41 have a higher speed of movement than the advancing speed of the feeding belts, each folding book 41 will during its movement along the bottom portion of plate 43 pass below the rear flap 1a of a box blank. In view of the fact that a plurality of folding hooks 41 is provided and due to their higher circulating speed, in each instance and without the necessity of maintaining a certain ryhthm it will be assured that each folding hook will engage the respective adjacent box blank. During the further advance, in conformity with the drawing, the rear flap is lifted while simultaneously the folding hook 41 is tilted in a direction counter to the circulating direction of chain 49. This tilting movement is made possible by the cutout 45 of the control plate 43. After each folding hook 41 with the lifted rear flap, while being tilted backwardly, has passed over the cutout 45 in control plate 45, the re spective folding hook is by means of its leg 44 automatically tilted forwardly when passing over the merging portion 46. Due to this additional relative movement of the respective folding hook 41 with regard to the box blank on the feeding belts, the rear flap is folded completely forwardly. In other words, the rear flap moves through the folding stages indicated in the drawing with 1', 1", 1" and 1 As will be evident from the above, a folding device according to the present invention makes it possible to fold forwardly also the rear flaps of the box blanks, for instance of a fiat folded box, by means of a continuously circulating device so that the heretofore known stepwise working devices are no longer necessary which frequently due to their complicated control contributed to disorders in the box making machine. The device according to the present invention is extremely simple, highly wear resistant, reliable in operation and low in cost. The employment of a folding device according to the present invention is not limited to the folding of the rear flaps of boxes of the above mentioned type but may also be employed in connection with any desired similar folding operations.

It is, of course, to be understood that the present invention is, by no means, limited to the particular arrangement shown in the drawing but also Comprises any modifications within the scope of the appended claims. It is also to be understood that the angle of inclination of the lower edge of plate 43 as it appears in the drawing does not represent a limitation but that also other angles are feasible.

What I claim is:

1. An apparatus for folding the trailing flaps of box blanks being fed along a horizontal path at a predetermined speed, which includes: a first rotatable sprocket wheel, a second rotatable sprocket wheel spaced in the horizontal direction from said first sprocket wheel in the direction of travel of said box blanks, said sprocket wheels having their axes of rotation extending horizontally and parallel to each other, an endless chain extending around said sprocket wheels for rotation thereby, whereby said chain travels through an upper path and around said first sprocket wheel into and through a lower path and around said second sprocket wheel back into said upper path, said chain along said lower path moving in the same direction as said box blanks but at a higher speed, a plurality of folding arms pivoted to said chain so as to be swingable thereon in the plane of the chain and uniformly spaced along the chain, each said arm being pivotally connected near one end to said chain and having a flap engaging portion on the other end which extends therefrom in the direction of travel of the chain along said lower path so as to be engageable beneath a flap to be folded from the rear, the lower path of said chain inclining upwardly from said first sprocket to said second sprocket and being so spaced from the path of said box blanks that said flap engaging portions are beneath said path of the blanks when the respective arms are moving along the first part of the lower path of the chain While the said portions are above the path of said blanks when the respective arms are moving along the last part of the lower path of the chain, said arms pivoting freely on said chains during the travel of the chain along the first part of the lower path thereof whereby said portions engage beneath trailing flaps on respective blanks from the rear and tilt the fiaps upwardly while the said arms simultaneously tilt backwardly on the chain, a cam engaging region on each said arm on the opposite side of the pivotal connection of the arm to the chain from said slap engaging portion thereof, and a cam adjacent the chain engageable with said cam engaging regions as the chain moves along the last portion of said lower path and operable for causing the arms to pivot on the chain to advance their fiap engaging portions in the direction of movement of the blanks and thereby complete the folding over of the tilted flaps engaged by said flap engaging portion.

2. An apparatus according to claim 1 in which abutment means are provided limiting the backward pivotal movement of each arm on the chain.

3. An apparatus according to claim 2 in which said cam engaging means on each arm comprises a leg on the extremity of said one end thereof extending in trailing direction.

4. An apparatus according to claim 3 in which said cam comprises a plate having an edge parallel to the chain and positioned to engage said cam engaging regions during the travel of the chain along the last part of the lower path thereof, said plate including an inclined approach at the leading end of said edge.

5. An apparatus according to claim 4 in which the said edge of said plate extends in parallel relation to said chain from the trailing end of said last part of the lower path of the chain around said second sprocket and along the upper path of the chain and around said first sprocket to the leading end of said first part of the lower path of the chain whereby said arms are freely pivotal on said chain only during the travel of the chain along said first part of the lower path thereof.

References Cited UNITED STATES PATENTS 2,774,286 12/1956 La Bombard 93-49 3,107,588 10/1963 Lobdell et a1. 93-53 BERNARD STICKNEY, Primary Examiner. 

